Mesoscopic Aharonov-Bohm Interferometers:Decoherence and Thermoelectric Transport
O. Entin-Wohlman, A. Aharony, Y. Imry
备注：
To be published in "In Memory of Akira Tonomura: Physicist and Electron Microscopist," Eds. Kazuo Fujikawa and Yoshimasa A. Ono (World Scientific, Singapore, 2013)
Two important features of mesoscopic Aharonov-Bohm (A-B) electronic interferometers are analyzed: decoherence due to coupling with other degrees of freedom and the coupled transport of charge and heat. We first review the principles of decoherence of electronic interference. We then analyze the thermoelectric transport in a ring threaded by such a flux, with a molecular bridge on one of its arms. The charge carriers may also interact inelastically with the molecular vibrations. This nano-system is connected to three termi- nals; two of them are electric and thermal, held at slightly different chemical potentials and temperatures, and the third is purely thermal. For example, a phonon bath thermalizing the molecular vibrations. When this third terminal is held at a temperature different from those of the electronic reservoirs, both an electrical and a heat current are, in general, gen- erated between the latter. Likewise, a voltage and/or temperature difference between the electronic terminals leads to thermal current between the thermal and electronic terminals. The transport coefficients governing these conversions (due to energy exchange between the electrons and the vibrations) and their dependences on the A-B flux are analyzed. Finally, the decoherence due to these inelastic events is discussed.
We briefly review the theoretical formulations and applications of the Aharonov--Bohm effect and the Aharonov--Casher effect with emphasis on mesoscopic physics. Topics relating to the Aharonov--Bohm effect include: locality, periodicity, non-integrable phase factors, Abelian gauge theory, interference, the spectrum and persistent current of electrons on a ring pierced by a magnetic field, Onsager reciprocity relations, and Aharonov--Bohm interferometer. Topics relating to the Aharonov--Casher effect include: a magnetic dipole in an electric field, locality, periodicity, non-Abelian gauge inva…
We predict the force-free scalar Aharonov-Bohm effect of a Cooper pair box in an electric field at a distance without forming a closed path of the interfering charges. The superposition of different charge states plays a major role in eliminating the closed loop, which is distinct from the original topological Aharonov-Bohm effect. The phase shift is determined by the charge-state-dependent local field interaction energy. In addition, our proposed setup does not require a pulse experiment for fast switching of a potential, which eliminates the major experimental obstacle for observing the idea…
We study combined interference effects due to the Aharonov-Bohm (AB) and Aharonov-Casher (AC) phases in a Josephson supercurrent of local and nonlocal (split) Cooper pairs. We analyze a junction between two superconductors interconnected through a normal-state nanostructure with either (i) a ring, where single-electron interference is possible, or (ii) two parallel nanowires, where the single-electron interference can be absent, but the cross Andreeev reflection can occur. In the low-transmission regime in both geometries the AB and AC effects can be related to only local or nonlocal Cooper pa…
The simultaneous effect of intense THz laser and in-plane electric fields on Aharonov-Bohm effect in single isotropic quantum rings is investigated using the non-perturbative Floquet theory in high-frequency limit. It is shown that in isotropic quantum rings the intense THz laser and in-plane electric field create unusual Aharonov-Bohm oscillations. For fixed values of intense THz laser field parameter, the amplitudes of Aharonov-Bohm oscillations can be effectively tuned by changing the electric field direction. Furthermore, for fixed values of electric field strength and laser field paramete…
Proximity induced quantum coherence of electrons in multi-terminal voltage-driven hybrid normal-superconducting nanostructures may result in a non-trivial interplay between topology-dependent Josephson and Aharonov-Bohm effects. We elucidate a trade-off between stimulation of the voltage-dependent Josephson current due to non-equilibrium effects and quantum dephasing of quasiparticles causing reduction of both Josephson and Aharonov-Bohm currents. We also predict phase-shifted quantum coherent oscillations of the induced electrostatic potential as a function of the externally applied magnetic …
Aharonov-Bohm Interferometry with Interacting Quantum Dots: Spin Configurations, Asymmetric Interference Patterns, Bias-Voltage-Induced Aharonov-Bohm Oscillations, and Symmetries of Transport Coefficients
Aharonov-Bohm interferences in the quantum Hall regime are observed when electrons are transmitted between two edge channels. Such a phenomenon has been realized in 2D systems such as quantum point contacts, anti-dots and p-n junctions. Based on a theoretical investigation of the magnetotransport in stepped graphene, a new kind of Aharonov-Bohm interferometers is proposed herewith. Indeed, when a strong magnetic field is applied in a proper direction, oppositely propagating edge states can be achieved in both terrace and facet zones of the step, leading to the interedge scatterings and hence s…
The effect of electron-phonon coupling on transport through a pair of strongly correlated quantum dots embedded in the Aharonov-Bohm ring is considered in the mean field slave boson Kotliar-Ruckenstein approach. It is shown that coupling with phonons opens transport gap in the region of double occupancy. Low-bias conductance and thermopower provide information on electron-phonon coupling strength.
Reply to "Comment on "Aharonov-Casher and Scalar Aharonov-Bohm Topological Effects""
在这个答复中，我们认为（一）汉密尔顿，方程。(17)在我们的论文中（Phys. Rev. Lett. 108，070405（2012）），绝对是洛伦兹不变量;（ii）生成拓扑Aharonov-Casher（AC）和标量Aharonov-Bohm（SAB）效应的条件是必要的和物理上有意义的;（iii）在Phys. Rev. Lett. 74，2847（1995）和arXiv：1311.4011不适合描述极化的旋量粒子。
Comment on "Aharonov-Casher and Scalar Aharonov-Bohm Topological Effects"
在这篇评论中，我们指出（i）哈密顿量，方程。(17)在信中（物理学评论Lett。108，070405（2012）），不是相对论性的哈密顿量，（ii）那么在信中的条件对于拓扑AC和SAB效应是不相关的，以及（iii）结论性地，Peshkin和Lipkin（Phys. Rev. Lett. 74，2847（1995））对于固定自旋具有相同的$U(1)_{mm}$规范结构，因此是正确的，但他们对自旋自相关的错误解释导致了错误的结论。
Topological Thouless pumping and Aharonov-Bohm effect are both fundamental effects enabled by the topological properties of the system. Here, we study both effects together: topological pumping of interacting particles through Aharonov-Bohm rings. This system can prepare highly entangled many-particle states, transport them via topological pumping and interfere them, revealing a fractional flux quantum. The type of the generated state is revealed by non-trivial Aharonov-Bohm interference patterns that could be used for quantum sensing. The reflections induced by the interference result from tr…
